Transverse connector

ABSTRACT

A transverse connector for coupling between first and second elongate members of a spinal stabilization system. The transverse connector includes a connector arm, a first coupling assembly proximate a first end of the arm, and a second coupling assembly proximate a second end of the arm. The first and second coupling assemblies are secured to the connector arm through a plurality of mating engagement features, such as dovetail grooves.

TECHNICAL FIELD

The disclosure is directed to transverse connectors for use in a spinalstabilization system. More particularly, the disclosure is directed totransverse connectors which may be attached between spinal rods in aspinal stabilization system.

BACKGROUND

The spinal column is a highly complex system of bones and connectivetissues that provides support for the body and protects the delicatespinal cord and nerves. The spinal column includes a series of vertebraestacked one on top of the other. Each vertebra includes a vertebral bodyincluding an inner or central portion of relatively weak cancellous boneand an outer portion of relatively strong cortical bone. Anintervertebral disc is situated between each vertebral body to cushionand dampen compressive forces experienced by the spinal column. Avertebral canal, called the foramen, containing the spinal cord andnerves is located posterior to the vertebral bodies. In spite of thecomplexities, the spine is a highly flexible structure, capable of ahigh degree of curvature and twist in nearly every direction. Forexample, the kinematics of the spine normally includes flexion,extension, rotation and lateral bending.

There are many types of spinal column disorders including scoliosis(abnormal curvature and twisting of the spine), kyphosis (abnormalforward curvature of the spine, usually in the thoracic spine), excesslordosis (abnormal backward curvature of the spine, usually in thelumbar spine), spondylolisthesis (forward displacement of one vertebraover another, usually in a lumbar or cervical spine) and other disorderscaused by abnormalities, disease, or trauma, such as spinal discherniation, degenerative disc disease, fractured vertebra, and the like.Patients that suffer from such conditions usually experience extreme anddebilitating pain as well as diminished range of motion and nervefunction. These spinal disorders may also threaten the critical elementsof the nervous system housed within the spinal column.

In some instances, a spinal stabilization system may be installed on asegment of the spinal column to stabilize a portion of the spinal columnto treat a spinal disorder. One particular spinal stabilizationtechnique includes immobilizing portions of the spine of a patient byusing elongate members such as relatively rigid orthopedic spinal rodsthat run generally parallel to the spine on opposite sides of thespinous processes.

Installation of such systems may be accomplished, for example, byaccessing the spine posteriorly and fastening hooks, bone screws, orother types of vertebral anchors to the pedicles or other bonystructures of the appropriate vertebrae. The vertebral anchors may begenerally placed in a quantity of two per vertebra, one on either sideof the spinous processes, and serve as anchor points for the elongatemembers.

It may be desirable in some circumstances to provide a cross connector,such as a transverse connector, to bridge across the spinal column froma first elongate member and associated assembly of vertebral anchors toa second elongate member and associated assembly of vertebral anchors ofthe spinal stabilization system to provide additional stability to thespinal stabilization system. Accordingly, there exists a need to providealternative transverse connector assemblies which may be coupled betweenfirst and second elongate members of a spinal stabilization system.

SUMMARY

The disclosure is directed to several alternative designs, materials andmethods of manufacturing medical device structures and assemblies.

Accordingly, one illustrative embodiment is a transverse connector forcoupling between first and second elongate members of a spinalstabilization system. The transverse connector may comprise a connectorarm having a first end portion, a second end portion and a bridge memberextending therebetween. The first end portion may have a first throughhole extending from a top surface to a bottom surface thereof and thesecond end portion may have a second through hole extending from a topsurface to a bottom surface thereof. The connector arm may furtherinclude a first upper pair of dovetail grooves extending along the topsurface adjacent to the first through hole, a first lower pair ofdovetail grooves extending along the bottom surface adjacent to thefirst through hole, a second upper pair of dovetail grooves extendingalong the top surface adjacent to the second through hole, and a secondlower pair of dovetail grooves extending along the bottom surfaceadjacent to the second through hole. A first coupling assembly may bepositioned proximate the first end portion of the connector arm. Thefirst coupling assembly may comprise a first sleeve having a topsurface, a bottom surface, an aperture extending between the top surfaceand the bottom surface, and a pair of dovetail grooves extending alongthe top surface. The first coupling assembly may further include a firstinsert having a first end region and a second end region and a firstlocking mechanism having a dovetail groove extending around a perimeterof a lower portion thereof. The transverse connector may further includea second coupling assembly positioned proximate to the second endportion of the connector arm. The second coupling assembly may comprisea second sleeve having a top surface, a bottom surface, an apertureextending between the top surface and the bottom surface, and a pair ofdovetail grooves extending along the top surface. The second couplingassembly may further include a second insert having a first end regionand a second end region and a second locking mechanism having a dovetailgroove extending around a perimeter of a lower portion thereof.

Another illustrative embodiment is a transverse connector for couplingbetween first and second elongate members of a spinal stabilizationsystem. The transverse connector may comprise a connector arm having afirst end portion, a second end portion and a bridge member extendingtherebetween along a longitudinal axis. The first end portion may have afirst through hole extending from a top surface to a bottom surfacethereof and the second end portion may have a second through holeextending from a top surface to a bottom surface thereof. The connectorarm may further include a first upper pair of dovetail grooves extendingalong the top surface adjacent to the first through hole, a first lowerpair of dovetail grooves extending along the bottom surface adjacent tothe first through hole, a second upper pair of dovetail groovesextending along the top surface adjacent to the second through hole, anda second lower pair of dovetail grooves extending along the bottomsurface adjacent to the second through hole. A first coupling assemblymay be positioned proximate to the first end portion of the connectorarm. The first coupling assembly may comprise a first sleeve having atop surface, a bottom surface, an aperture extending between the topsurface and the bottom surface, and a pair of dovetail grooves extendingalong the top surface and configured to slidably engage the first pairof lower dovetail grooves of the connector arm in a direction generallyparallel to the longitudinal axis of the connector arm. The firstcoupling assembly may further comprise a first insert having a first endregion and a second end region, the first insert being movably disposedwithin the aperture of the first sleeve and a first locking mechanismhaving a dovetail groove extending around a perimeter of a lower portionthereof and configured to slidably engage the first pair of upperdovetail grooves of the connector arm in a direction generally parallelto the longitudinal axis of the connector arm. The transverse connectormay further include a second coupling assembly proximate the second endportion of the connector arm. The second coupling assembly may comprisea second sleeve having a top surface, a bottom surface, an apertureextending between the top surface and the bottom surface, and a pair ofdovetail grooves extending along the top surface and configured toslidably engage the second pair of lower dovetail grooves of theconnector arm in a direction generally parallel to the longitudinal axisof the connector arm. The second coupling assembly may further comprisea second insert having a first end region and a second end region, thesecond insert being movably disposed within the aperture of the secondsleeve and a second locking mechanism having a dovetail groove extendingaround a perimeter of a lower portion thereof and configured to engagethe second pair of upper dovetail grooves of the connector arm in adirection generally parallel to the longitudinal axis of the connectorarm.

Another illustrative embodiment is a spinal stabilization system. Thespinal stabilization system may comprise a first and a second elongatemember. A transverse connector may extend between the first elongatemember and the second elongate member. The transverse connector maycomprise a connector arm having a first end portion, a second endportion and a bridge member extending therebetween, the first endportion having a first through hole extending from a top surface to abottom surface and the second end portion having a second through holeextending from a top surface to a bottom surface. The connector arm mayfurther include a first upper pair of dovetail grooves extending alongthe top surface adjacent to the first through hole, a first lower pairof dovetail grooves extending along the bottom surface adjacent to thefirst through hole, a second upper pair of dovetail grooves extendingalong the top surface adjacent to the second through hole, and a secondlower pair of dovetail grooves extending along the bottom surfaceadjacent to the second through hole. The transverse connector mayfurther include a first coupling assembly proximate the first endportion of the connector arm. The first coupling assembly may comprise afirst sleeve having a top surface, a bottom surface, an apertureextending between the top surface and the bottom surface, and a pair ofdovetail grooves extending along the top surface. The first couplingassembly may further comprise a first insert having a first end regionand a second end region and a first locking mechanism having a dovetailgroove extending around a perimeter of a lower portion thereof. Thetransverse connector may further include a second coupling assemblyproximate the second end portion of the connector arm. The secondcoupling assembly may comprise a second sleeve having a top surface, abottom surface, an aperture extending between the top surface and thebottom surface, and a pair of dovetail grooves extending along the topsurface. The second coupling assembly may further include a secondinsert having a first end region and a second end region and a secondlocking mechanism having a dovetail groove extending around a perimeterof a lower portion thereof.

The above summary of some example embodiments is not intended todescribe each disclosed embodiment or every implementation of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIG. 1 is a perspective view of an exemplary spinal stabilization systemincluding a transverse connector extending between elongate members;

FIG. 2 is a perspective view of the transverse connector shown in FIG.1;

FIG. 3 is a cross-sectional view of the transverse connector of FIG. 2taken along line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view of a coupling portion of the transverseconnector of FIG. 2 taken along line 4-4 of FIG. 2; and

FIG. 5 is an exploded perspective view of components of a couplingportion of the transverse connector of FIG. 2.

FIG. 6 is another perspective view of components of a coupling portionof the transverse connector of FIG. 2.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit aspects of thedisclosure to the particular embodiments described. On the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the disclosure.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimensions, ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the disclosure. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

Now referring to the drawings, an exemplary spinal stabilization system2 for stabilizing a portion of a spinal column, such as one or morespinal segments of a spinal column, is illustrated in FIG. 1. As usedherein, a spinal segment is intended to refer to two or more vertebrae,the intervertebral disc(s) between the vertebrae and other anatomicalelements between the vertebrae. For example, a spinal segment mayinclude first and second adjacent vertebrae and the intervertebral disclocated between the first and second vertebrae. The spinal stabilizationsystem 2 may provide support to the spinal segment subsequent bonefusion, may help preserve the facet joints between adjacent vertebrae byproviding facet offloading and/or may stabilize or reverse neuralforaminal narrowing of the spinal column, in some instances.

In some embodiments, the spinal stabilization system 2 may be used totreat discogenic low back pain, degenerative spinal stenosis, discherniations, facet syndrome, posterior element instability, adjacentlevel syndrome associated with spinal fusion, and/or other maladiesassociated with the spinal column.

The spinal stabilization system 2 may include one or more or a pluralityof vertebral anchors 10 and elongate members 4 extending therebetween.Although the vertebral anchors 10 are depicted as threaded vertebralfasteners (e.g., pedicle screws, bone screws), in some embodiments thevertebral anchors 10 may be vertebral hooks (e.g., laminar hooks) orother types of fastening members for attachment to a bony structure suchas a vertebra of the spinal column. Each of the vertebral anchors 10 maybe configured to be secured to a vertebra of a spinal column.

The spinal stabilization system 2 may be used in any desired region ofthe spinal column, such as the cervical, thoracic, thoracolumbar, andlumbar regions. The vertebral stabilization system 2 may be installedmulti-laterally on opposite sides of the sagittal plane of the spinalcolumn, with the first and third vertebral anchors 10 a, 10 c and thefirst elongate member 4 a positioned on one lateral side of the sagittalplane and the second and fourth vertebral anchors 10 b, 10 d and thesecond elongate member 4 b positioned on the other lateral side (i.e.,contra-lateral side) of the sagittal plane. For instance, the firstvertebral anchor 10 a and the second vertebral anchor 10 b may besecured to a first vertebra on contra-lateral sides of the sagittalplane, while the third vertebral anchor 10 c and the fourth vertebralanchor 10 d may be secured to a second vertebra on contra-lateral sidesof the sagittal plane. Additional vertebral anchors 10 may be secured toadditional vertebrae as desired.

The vertebral anchor 10 may include a housing 12 and a bone engagementportion, such as a bone screw 14 extending from the housing 12 along alongitudinal axis of the vertebral anchor 10. In some embodiments, thevertebral anchor 10 may be a monoaxial screw in which the housing 12 isstationary relative to the bone screw 14, while in other embodiments thevertebral anchor 10 may be a polyaxial screw in which the housing 12 isactuatable (e.g., pivotable) relative to the bone screw 14. In yet otherembodiments, the vertebral anchor may be a monoaxial screw, a uniplanarscrew, a bone hook, or the like. In some embodiments, the bone screw 14may be configured to be installed into a bony region of a vertebra ofthe spinal column. For example, the bone screw 14 may be installed intoa pedicle of a vertebra, or other region of a vertebra. In someembodiments, the bone screw 14 may include helical threads configured tobe screwed into a pedicle of a vertebra, or other bony region of avertebra.

The housing 12 may include a base portion and first and second legs 8extending from the base portion and defining a channel 6, such as aU-shaped channel, therebetween extending into the housing 12 from anupper extent of the housing 12 opposite the bone screw 14. In someembodiments each of the first and second legs 8 may include a threadedportion for threadedly engaging a threaded portion of a fastener 16. Inother embodiments, the first and second legs 8 may include otherengagement features for engaging with a securing member positioned inthe housing 12 between the first and second legs 8.

The spinal stabilization system 2 may also include one or more, or aplurality of elongate stabilization members 4 a, 4 b (collectively 4),such as elongate rods, extending between vertebral anchors 10 of thespinal stabilization system 2. As an illustrative example, the spinalstabilization system 2 shown in FIG. 1 includes a first elongate member4 a extending between and secured to the first vertebral anchor 10 a andthe third vertebral anchor 10 c, and a second elongate member 4 bextending between and secured to the second vertebral anchor 10 b andthe fourth vertebral anchor 10 d.

The elongate members 4 may be secured in the channels 6 of the housings12 of the vertebral anchors 10 using threaded fasteners or othersecurement members. For instance, threaded set screws 16 may bethreadably engaged with the threaded portions of the legs 8 of thehousings 12 of the vertebral anchors 10 and press against the elongatemember 4 to secure the elongate members 4 in the channels 6.

The spinal stabilization system 2 may also include a transverseconnector 20 which may be positioned generally perpendicular to theelongate members 4 to provide additional stability to the spinalstabilization system 2 in some instances. The transverse connector 20may be configured to be coupled to the elongate stabilization members 4.For example, the transverse connector 20 may be coupled between thefirst and second stabilization members 4 a, 4 b in an orientationgenerally perpendicular to the elongate members 4. Opposing ends of thetransverse connector 20 may include coupling assemblies 22, eachconfigured to engage an elongate member 4.

While the transverse connector 20 is illustrated as being positionedbetween contralateral spinal rods on either lateral side of sagittalplane at a single spinal level, it is contemplated that the transverseconnector 20 may be configured to allow for multilevel connection insome instances. In other words, in some instances, the first couplingassembly 22 a may be coupled to a first elongate member 4 between afirst vertebra and a second vertebra on a first lateral side of thesagittal plane, and the second coupling assembly 22 b may be coupled toa second elongate member 4 between the second vertebra and a thirdvertebra on a second lateral side of the sagittal plane opposite thefirst lateral side. For example, in some instances, a first couplingassembly 22 a may be positioned between the C3 and C4 vertebrae and asecond coupling assembly 22 b may be positioned between the C4 and C5vertebrae. In such an instance, the transverse connector 20 may bepositioned at an oblique angle to the elongate members 4. This is justan example; it is contemplated that the first and second couplingassemblies 22 a, 22 b may be positioned between any vertebrae desired.

It is further contemplated that the transverse connector 20 may beconfigured to attach to the housing 12 of one or more of the vertebralanchors 10 in some instances. For example, the insert 38 of the couplingassembly 22 may be configured to clamp onto the housing 12 of avertebral anchor 10, or other structural component of a vertebral anchor10, if desired.

Additional features and components of the transverse connector 20 arefurther illustrated in FIGS. 2-6. As shown in FIG. 2, which illustratesa perspective view of the transverse connector 20, the transverseconnector 20 may include a connector arm 24 having a first end portion26, a second end portion 28, and a bridge member 32 extending betweenthe first end portion 26 and the second end portion 28. The bridgemember 32 may have an arcuate or curved shape, although this is notrequired. The first and second end portions 26, 28 may each include athrough hole 30 extending therethrough. In some instances, the throughholes 30 may have a generally oblong or elongated shape, although thisis not required. It is contemplated that the through holes 30 may takeany shape desired, such as, but not limited to, round, square,rectangular, polygonal, etc. In some instances, the through holes 30 maybe sized to allow for some longitudinal movement of coupling assemblies22 in direction L such that the transverse connector 20 can be adaptedto the varying anatomies of different patients. An upper surface 34 anda lower surface (not explicitly shown) may surround a perimeter of eachof the through holes 30. In some instances, the upper surface 34 and thelower surface may be a textured surface 35 to help secure the couplingassemblies 22. In some embodiments, the textured surface 35 may begrooved, ridged, bumped, etc., to increase the surface area of thesurface and/or to increase the friction between the connector arm 24 andthe coupling assemblies 22.

Referring additionally to FIG. 3, which illustrates a cross-sectionalview of transverse connector 20 taken at line 3-3 of FIG. 2, thetransverse connector 20 may include a first coupling assembly 22 a and asecond coupling assembly 22 b secured to the connector arm 24 at each ofthe through holes 30. The first coupling assembly 22 a is shown in afirst configuration and the second coupling assembly 22 b is shown in asecond configuration, as will be described in more detail below. It isnoted that although the coupling assemblies 22 a, 22 b are shown in twodifferent configurations, the coupling assemblies 22 may be similarlyconfigured and include similar components.

Each coupling assembly 22 may include multiple components, including aninsert 38, a sleeve 36, and a locking mechanism 40 cooperating to secureconnector arm 24 between two elongate members 4. It is noted thatalthough one coupling assembly 22 at one end of the transverse connector20 is described herein, the coupling assembly 22 at the other end of thetransverse connector 20 may be similarly configured and include similarcomponents. The sleeve 36 may include a central aperture 42 extendingfrom a top surface 44 to a bottom surface 46 of the sleeve 36. Theaperture 42 may have a first end region 48 having a generally constantcross-sectional shape adjacent to the top surface 44. The aperture 42may have a second end region 50 which tapers from a first cross-sectionshape adjacent to the bottom surface 46 towards a second, smallercross-sectional shape adjacent to the first end region 48. In someinstances, the second end region 50 may, in part, have a generallyconical tapered surface shaped to contact an outer surface of the insert38, as will be discussed in more detail below. It is contemplated thatthe second end region 50 may slope at an angle of approximately 20°,approximately 25°, or approximately 30°, although this is not required.It is contemplated that the slope may be any oblique angle to thelongitudinal axis of the aperture 42 desired.

The insert 38 may be slidably disposed within the aperture 42 of thesleeve 36 and the through hole 30 of the connector arm 24. For example,the insert 38 may move up and down within the aperture 42 of the sleeve36 along the longitudinal rotational axis of the insert 38, as will bediscussed in more detail below. Furthermore, the insert 38 may slidetogether with the sleeve 36 along the direction L of FIG. 2. The insert38 may include a first end region 52 and a second end region 54. Thefirst end region 52 may include a threaded portion 56, such as anexternally threaded post portion, configured to engage a threadedportion 60, such as an internally threaded bore, of the lockingmechanism 40 and flat regions 58 (see FIGS. 4 and 5). The flat regions58 may allow for some rotation, for example ±10° from the longitudinalaxis of the transverse connector 20, yet prevent the insert 38 fromfully rotating 360° within the through hole 30. The aperture 42 of thesleeve 36 may also include features to limit the rotation of the insert38, as will be discussed in more detail below. The ability of the insert38 to rotate through a limited amount of rotation, such as an angle lessthan 360°, less than 180°, less than 90°, less than 45°, or less than30° may allow the transverse connector 20 to extend between two elongatemembers 4 that are not parallel. The distance across the insert 38between the flat regions 58 and perpendicular to the longitudinal axisof the insert 38 may be less than the width of the through hole 30 ofthe connector arm 24 and the portion of the aperture 42 of the sleeve 36through which the threaded portion 56 extends, while the transversedistance across the insert 38 between the discontinuous threadedportions between the flat region 58 and perpendicular to thelongitudinal axis of the insert 38 may be greater than the width of thethrough hole 30 such that the insert 38 may be positioned through thethrough hole 30, while restricting rotation movement of the insert 38 inthe hole 30.

The first end region 52 may extend through the aperture 42 of the sleeve36 and through hole 30 in the connector arm 24. The locking mechanism 40may threadably engage insert 38 to secure the insert 38 to the connectorarm 24. For instance, the threaded portion of the locking mechanism 40may threadably mate with the threaded portion of the insert 38. In someinstances, the locking mechanism 40 may be a nut, although this is notrequired. A divot 100 may be formed adjacent to the threaded portion 56.

The second end region 54 of the insert 38 may include a pair of angledarms 54 each having an arcuate or curved inner surface 64 a, 64 b(collectively 64). The curved inner surfaces 64 may be sized and shapedto generally conform to or grasp an outer surface of elongate member 4.In some instances, the center of radius of the radius cuts forming thecurved inner surfaces 64 a, 64 b may not be co-located. For example, thecenter of radius of the radius cut of the first curved inner surface 64a may be offset from the longitudinal axis of the insert in a firstdirection and the center of radius of the radius cut of the secondcurved inner surface 64 b may be offset from the longitudinal axis ofthe insert 38 in a second direction generally opposite from the firstdirection. Offseting the centers of radii of the curved inner surfaces64 a, 64 b may reduce or minimize the amount of force required to snapthe insert 38 onto the elongate member 4. It is contemplated that whenthe arms 62 are compressed by the sleeve 36, as discussed in more detailbelow, the arms 62 are moved inward towards one another such that thecenter of radii of the radius cuts are generally aligned along the samecentral axis of the elongate member 4.

The insert 38 may further include an opening or gap 66 between the arms62 to allow the arms 62 to flex inwards towards one another, as will bedescribed in more detail below. The opening between the arms 54 may besized to be slightly less than the diameter of the elongate member 4positionable therein, such that the insert 38 snaps onto the elongatemember 4 and surrounds more than 180° of the elongate member 4 toprovisionally couple the insert 38 to the elongate member 4 prior tolocking the transverse connector 20 to the elongate member 4 with thelocking mechanism 40. Referring to FIG. 4, which illustrates across-sectional view of transverse connector 20 taken at line 4-4 ofFIG. 2, and FIG. 5, which illustrates a perspective view of a partiallyexploded transverse connector 20, the locking mechanism 40 and sleeve 36may be releasably connected to the connector arm 24 through a series ofmating engagement or retention elements, such as, but not limited todovetail features (e.g., mating dovetail flanges and/or grooves). Whilethe engagement elements or members are described as dovetail grooves, itis contemplated that the locking mechanism 40, sleeve 36, and connectorarm 24 may include a variety of structural features configured toreleasably secure the locking mechanism 40 and sleeve 36 to theconnector arm 24. These structural features include but are not limitedto mating dovetail grooves, a tongue and groove structure, flanges andcorresponding grooves, pins or other protruding elements, etc.

The lower surface of the connector arm 24 may include an engagementfeature, for example, a pair of lower grooves, such as dovetail grooves68, and/or the upper surface of the connector arm 24 may include anengagement feature, for example, and a pair of upper grooves, such asdovetail grooves 70. The engagement features (e.g., dovetail grooves 68,70) may extend generally parallel to a longitudinal axis of theconnector arm 24 on either side of the through hole 30. The sleeve 36,which may be positioned below the connector arm 24, may include anengagement feature, for example, a pair of flanges and/or grooves, suchas dovetail grooves or flanges 72 positioned adjacent to the top surface34 thereof configured to mate with the engagement feature (e.g.,dovetail grooves 68) on the lower surface of the connector arm 24. Theengagement features (e.g., dovetail grooves 72) may extend along the topsurface 44 from a first end 76 to a second end 78 and adjacent to afirst side 80 and a second side 82 (see FIG. 5) of the sleeve 36. Thelower engagement feature (e.g., dovetail grooves 68) may have an openregion (not explicitly shown) near the first end 84 (or second end 86)of the connector arm 24 such that the engagement feature (e.g., dovetailgrooves 72) on the sleeve 36 may be slidably engaged with the engagementfeature (e.g., dovetail grooves 68) on the lower surface of theconnector arm 24. It is contemplated that when the engagement features(e.g., dovetail grooves 68, 72) are engaged with one another, the sleeve36 may be held in a position adjacent to the lower surface 88 of theconnector arm 24, as shown in FIG. 4.

The locking mechanism 40, which may be positioned above the connectorarm 24, may include an engagement feature, for example, a flange, suchas a dovetail groove or flange 74 extending around a circumference ofthe lower portion 90 thereof. The upper engagement feature (e.g.,dovetail grooves 70) of the connector arm 24 may have an open region 92near the first end 84 (or second end 86) of the connector arm 24 suchthat the engagement feature or flange (e.g., dovetail groove 74) on thelocking mechanism 40 may be slidably engaged with the engagement feature(e.g., dovetail grooves 70) on the upper surface of the connector arm24. The circumferential flange (e.g., dovetail groove 74) may allow thelocking mechanism 40 to rotate relative to the connector arm 24, thesleeve 36 and/or the insert 38 while releasably securing the lockingmechanism 40 to the connector arm 24 via mating engagement features(e.g., dovetail grooves 70, 74).

To assemble the transverse connector 20, the sleeve 36 may be slid ontothe connector arm 24 in a direction generally parallel to thelongitudinal axis of the transverse connector 20 with the engagementfeature (e.g., flanges, grooves, dovetail grooves 72) of the sleeve 36mating with the lower engagement feature (e.g., flanges, grooves,dovetail grooves 68) of the connector arm 24. The locking mechanism 40may be slid onto the connector arm 24 in a direction generally parallelto the longitudinal axis of the transverse connector 20 with theengagement feature (e.g., flange, groove, dovetail groove 74) of thelocking mechanism 40 mating with the upper engagement feature (e.g.,flanges, grooves, dovetail grooves 70) of the connector arm 24. Thesleeve 36 and the locking mechanism 40 may be vertically aligned suchthat the aperture 42 in the sleeve 36 generally aligns with a throughhole 94 (e.g., threaded bore) in the locking mechanism 40. The first endregion 52 (e.g., threaded post) of the insert 38 may then be insertedupwards through the aperture 42 in the sleeve 36 until it begins toengage the locking mechanism 40, as shown in connector assembly 22 a inFIG. 3. The locking mechanism 40 may then be rotated to threadablyengage the locking mechanism 40 with the insert 38. Rotating in a firstdirection, such as clockwise, or tightening the locking mechanism 40 mayraise the second end region 54 of the insert 38 into the aperture 42 ofthe sleeve 36, as shown in connector assembly 22 b in FIG. 3. As theinsert 38 is drawn into the aperture 42 of sleeve 36, an outer surface96 of the arms 62 may contact an inner surface 98 (see FIG. 6) of thesleeve 36. The inner surface 98 may have a generally conical taperedsurface shaped to contact the outer surface 96 of the insert 38. It iscontemplated that the inner surface 98 may slope at an angle ofapproximately 20°, for example, although this is not required. It iscontemplated that the slope may be any oblique angle to the longitudinalaxis of the insert 38 desired. The inner surface 98 of the sleeve 36 maybe sized and shaped such that the arms 62 of the insert 38 form a pointand/or line contact with the inner surface 98. It is furthercontemplated that the second end region 50 of aperture 42 may beslightly smaller than the outer profile of the arms 62 of the insert 38.This may cause the arms 62 to compress towards one another when the arms62 are disposed within the sleeve 36, allowing the insert 38 to graspthe elongate member 4 positioned therebetween. Rotating the lockingmechanism 40 in a second direction opposite the first direction, such ascounter-clockwise, or loosening the locking mechanism 40, may cause theinsert 38 to lower out of the housing 36. The mating engagement features(e.g., flanges, grooves, dovetail grooves 68, 72) of the connector arm24 and the sleeve 36 may allow the insert 38 to be raised and loweredwhile maintaining the sleeve 36 in a desired position. For example, themating engagement features (e.g., flanges, grooves, dovetail grooves 68,72) of the connector arm 24 and the sleeve 36 may hold the sleeve 36 upand juxtaposed with the lower surface of the connector arm 24 while theinsert 38 is lowered to engage the elongate member 4. When the surfaces96 of the insert 38 is lowered away from the inner surface 98 of thesleeve 36, the arms 62 of the insert 38 may be slayed or deflectedoutward to permit the elongate member 4 to be inserted into the openingbetween the arms 62.

In some embodiments, the channel extending through the sleeve 36 foraccommodating the elongate member 4 therethrough may include one or morerecesses 97 opening out on opposing sides of the sleeve 36. The recesses97 may be positioned adjacent to a central inner conical surface 98. Therecesses 97 permit the elongate member 4 to extend at anon-perpendicular angle to the transverse connector 20, and thereforeallow for increased angulation of the elongate member 4 relative to thelongitudinal axis of the transverse connector 20. For example, therecesses 97 may allow the transverse connector 20 to extend between twoelongate members 4 without being perpendicular to one or more of theelongate members 4. For example, the transverse connector 20 may extendat an oblique angle to one or more of the elongate members 4, such as atan angle between about 30° to 90°, between about 45° to 90°, or betweenabout 60° to 90° from the elongate member 4. Thus the transverseconnector 20, including the sleeve 36, may be rotated relative to theinsert 38 about the longitudinal axis of the insert 38 with the insert38 clipped onto the elongate member 4 before final tightening of thelocking mechanism 40 to secure the transverse connector 20 to theelongate member 4.

It is contemplated that the transverse connector 20 may be shipped tothe customer in its assembled state. To couple the transverse connector20 between two elongate members 4, the physician may rotate the lockingmechanism 40 to lower the insert 38 out of the sleeve 36 as shown incoupling assembly 22 a in FIGS. 2 and 3, if so needed. In someinstances, the transverse connector 20 may be provided with the insert38 lowered out of the sleeve 36 as shown in coupling assembly 22 a inFIGS. 2 and 3. The arms 62 of the insert 38 may be deflected around theelongate members 4 to couple the elongate members 4 thereto. The lockingmechanism 40 may then be rotated to raise the insert 38 into the sleeve36 and thereby draw the surfaces 96 of the arms 62 of the insert 38 intocontact with the inner surface 98 of the sleeve 36 as shown in couplingassembly 22 b in FIGS. 2 and 3. As discussed above, the inner surface 98of the sleeve 36 may apply a compressive force on the outer surface 96of the arms 62 to further secure the elongate member 4 between the arms62.

In some instances, the threaded region 60 of the locking mechanism 40may have a major diameter D1 and a minor diameter D2 (see FIG. 4). Themajor diameter D1 may remain constant over the length of the threadedregion 60. In some embodiments, the minor diameter D2 may taper from afirst diameter proximate an upper end 95 of the threaded region 60 to asecond smaller diameter adjacent to the lower portion 90, although thisis not required. It is contemplated that the minor diameter D2 maychange in a step-wise manner over the length of the threaded region 60,or gradually, for example. In some instances, there may be two or moredifferent minor diameters D2 over the length of the threaded region 60.In some instances, the minor diameter D2 may remain constant over thelength of the threaded region 60.

It is contemplated that subsequent to threading the threaded region 56of the insert 38 into the threaded region 60 of the locking member 40from the lower portion 90 toward the upper end 95 of the lockingmechanism 40, the upper end of the threaded portion 56 of the insert 38may be flared outward sufficiently to prevent the flared upper portionfrom coming unthreaded from the locking mechanism 40. For example, thethreading of the flared upper portion of the insert 38 may have a majordiameter less than the major diameter D1 of the threaded region 60,while the minor diameter of the flared upper portion of the insert 38may be less than the minor diameter D2 proximate the upper end 95 of thethreaded region 60 yet greater than the minor diameter D2 proximate thelower portion 90 of the threaded region 60. Accordingly, the flaredupper portion of the insert 38 may hang up on the smaller minor diameterD2 proximate the lower portion 90 of the locking mechanism 40 to couplethe insert 38 and locking mechanism 40 together, and thus prevent thetwo components from being decoupled.

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent invention as described in the appended claims.

What is claimed is:
 1. A transverse connector for coupling between firstand second elongate members of a spinal stabilization system, thetransverse connector comprising: a connector arm having a first endportion, a second end portion and a bridge member extendingtherebetween, the first end portion having a first through holeextending from a top surface to a bottom surface and the second endportion having a second through hole extending from a top surface to abottom surface, wherein the connector arm further includes a first upperpair of dovetail grooves extending along the top surface adjacent to thefirst through hole, a first lower pair of dovetail grooves extendingalong the bottom surface adjacent to the first through hole, a secondupper pair of dovetail grooves extending along the top surface adjacentto the second through hole, and a second bottom pair of dovetail groovesextending along the lower surface adjacent to the second through hole; afirst coupling assembly proximate the first end portion of the connectorarm, the first coupling assembly comprising: a first sleeve having a topsurface, a bottom surface, an aperture extending between the top surfaceand the bottom surface, and a pair of dovetail grooves extending alongthe top surface configured to slidably engage the first lower pair ofdovetail grooves of the connector arm; a first insert extending throughthe first through hole, the first insert having a first end region and asecond end region; and a first locking mechanism coupled to the firstinsert and having a dovetail groove extending around a perimeter of alower portion thereof configured to slidably engage the first upper pairof dovetail grooves of the connector arm; a second coupling assemblyproximate the second end portion of the connector arm, the secondcoupling assembly comprising: a second sleeve having a top surface, abottom surface, an aperture extending between the top surface and thebottom surface, and a pair of dovetail grooves extending along the topsurface configured to slidably engage the second lower pair of dovetailgrooves of the connector arm; a second insert extending through thesecond through hole, the second insert having a first end region and asecond end region; and a second locking mechanism coupled to the secondinsert and having a dovetail groove extending around a perimeter of alower portion thereof configured to slidably engage the second upperpair of dovetail grooves of the connector arm.
 2. The transverseconnector of claim 1, wherein the first insert is rotatable in the firstthrough hole through an angle of less than 360° and the second insert isrotatable in the second through hole through an angle of less than 360°.3. The transverse connector of claim 1, wherein the connector arm has alongitudinal axis and the first sleeve and the first locking mechanismare configured to slidingly engage the first lower pair of dovetailgrooves and the first upper pair of dovetail grooves, respectively, ofthe connector arm in a first direction generally parallel to thelongitudinal axis of the connector arm and the second sleeve and thesecond locking mechanism are configured to slidingly engage the secondlower pair of dovetail grooves and the second upper pair of dovetailgrooves, respectively, of the connector arm in a second directiongenerally parallel to the longitudinal axis of the connector arm andopposite the first direction.
 4. The transverse connector of claim 1,wherein first end region of each of the first and second insertscomprises a threaded region.
 5. The transverse connector of claim 4,wherein each of the first and second locking mechanisms comprises athreaded through hole.
 6. The transverse connector of claim 5, whereinthe first and second locking mechanisms are configured to threadablyengage the threaded region of the first and second inserts,respectively.
 7. The transverse connector of claim 6, wherein rotatingeither of the first or second locking mechanisms in a first directionraises the corresponding insert into the aperture of the sleeve.
 8. Thetransverse connector of claim 7, wherein rotating either of the first orsecond locking mechanisms in a second direction, opposite the firstdirection, lowers the corresponding insert out of the aperture of thesleeve.
 9. The transverse connector of claim 1, wherein the second endregion of each of the first and second inserts comprises two deflectablearms.
 10. The transverse connector of claim 9, wherein the deflectablearms of each of the first and second inserts are configured to engage anelongate member of a spinal stabilization system.
 11. A transverseconnector for coupling between first and second elongate members of aspinal stabilization system, the transverse connector comprising: aconnector arm having a first end portion, a second end portion and abridge member extending therebetween along a longitudinal axis, thefirst end portion having a first through hole extending from a topsurface to a bottom surface and the second end portion having a secondthrough hole extending from a top surface to a bottom surface, whereinthe connector arm further includes a first upper pair of dovetailgrooves extending along the top surface adjacent to the first throughhole, a first lower pair of dovetail grooves extending along the bottomsurface adjacent to the first through hole, a second upper pair ofdovetail grooves extending along the top surface adjacent to the secondthrough hole, and a second lower pair of dovetail grooves extendingalong the bottom surface adjacent to the second through hole; a firstcoupling assembly proximate the first end portion of the connector arm,the first coupling assembly comprising: a first sleeve having a topsurface, a bottom surface, an aperture extending between the top surfaceand the bottom surface, and a pair of dovetail grooves extending alongthe top surface and configured to slidably engage the first pair oflower dovetail grooves of the connector arm in a direction generallyparallel to the longitudinal axis of the connector arm; a first inserthaving a first end region and a second end region, the first insertmovably disposed within the aperture of the first sleeve; and a firstlocking mechanism having a dovetail groove extending around a perimeterof a lower portion thereof and configured to slidably engage the firstpair of upper dovetail grooves of the connector arm in a directiongenerally parallel to the longitudinal axis of the connector arm; asecond coupling assembly proximate the second end portion of theconnector arm, the second coupling assembly comprising: a second sleevehaving a top surface, a bottom surface, an aperture extending betweenthe top surface and the bottom surface, and a pair of dovetail groovesextending along the top surface and configured to slidably engage thesecond pair of lower dovetail grooves of the connector arm in adirection generally parallel to the longitudinal axis of the connectorarm; a second insert having a first end region and a second end region,the second insert movably disposed within the aperture of the secondsleeve; and a second locking mechanism having a dovetail grooveextending around a perimeter of a lower portion thereof and configuredto slidably engage the second pair of upper dovetail grooves of theconnector arm in a direction generally parallel to the longitudinal axisof the connector arm.
 12. The transverse connector of claim 11, whereinfirst end region of each of the first and second inserts comprises athreaded region and the second end region of each of the first andsecond inserts comprises two deflectable arms.
 13. The transverseconnector of claim 12, wherein the deflectable arms of each of the firstand second inserts are configured to engage an elongate member of aspinal stabilization system.
 14. The transverse connector of claim 12,wherein each of the first and second locking mechanisms comprises athrough hole having a threaded region, the threaded region having amajor diameter and a minor diameter, wherein the minor diameterdecreases towards the lower portion of the locking mechanisms.
 15. Thetransverse connector of claim 14, wherein the first and second lockingmechanisms are configured to threadably engage the threaded region ofthe first and second inserts, respectively.
 16. The transverse connectorof claim 15, wherein rotating either of the first or second lockingmechanisms in a first direction raises the corresponding insert into theaperture of the sleeve.
 17. The transverse connector of claim 16,wherein rotating either of the first or second locking mechanisms in asecond direction, opposite the first direction, lowers the correspondinginsert out of the aperture of the sleeve.
 18. A spinal stabilizationsystem comprising: a first elongate member; a second elongate member; atransverse connector extending between the first elongate member and thesecond elongate member, the transverse connector comprising: a connectorarm having a first end portion, a second end portion and a bridge memberextending therebetween, the first end portion having a first throughhole extending from a top surface to a bottom surface and the second endportion having a second through hole extending from a top surface to abottom surface, wherein the connector arm further includes a first upperpair of dovetail grooves extending along the top surface adjacent to thefirst through hole, a first lower pair of dovetail grooves extendingalong the bottom surface adjacent to the first through hole, a secondupper pair of dovetail grooves extending along the top surface adjacentto the second through hole, a second lower pair of dovetail groovesextending along the bottom surface adjacent to the second through hole;a first coupling assembly proximate the first end portion of theconnector arm, the first coupling assembly comprising: a first sleevehaving a top surface, a bottom surface, an aperture extending betweenthe top surface and the bottom surface, and a pair of dovetail groovesextending along the top surface slidably engaged with the first lowerpair of dovetail grooves of the connector arm; a first insert extendingthrough the first through hole, the first insert having a first threadedend region and a second end region coupled to the first elongate member;and a first locking mechanism threadably engaged with the first threadedend region of the first insert, the first locking mechanism having adovetail groove extending around a perimeter of a lower portion thereofengaged with the first upper pair of dovetail grooves of the connectorarm; a second coupling assembly proximate the second end portion of theconnector arm, the second coupling assembly comprising: a second sleevehaving a top surface, a bottom surface, an aperture extending betweenthe top surface and the bottom surface, and a pair of dovetail groovesextending along the top surface slidably engaged with the second lowerpair of dovetail grooves of the connector arm; a second insert extendingthrough the second through hole, the second insert having a firstthreaded end region and a second end region coupled to the secondelongate member; and a second locking mechanism threadably engaged withthe first threaded end region of the second insert, the second lockingmechanism having a dovetail groove extending around a perimeter of alower portion thereof engaged with the second upper pair of dovetailgrooves of the connector arm.
 19. The spinal stabilization system ofclaim 18, wherein the connector arm has a longitudinal axis and thefirst sleeve and the first locking mechanism are configured to slidinglyengage the first lower pair of dovetail grooves and the first upper pairof dovetail grooves, respectively, of the connector arm in a firstdirection generally parallel to the longitudinal axis of the connectorarm and the second sleeve and the second locking mechanism areconfigured to slidingly engage the second lower pair of dovetail groovesand the second upper pair of dovetail grooves, respectively, of theconnector arm in a second direction generally parallel to thelongitudinal axis of the connector arm and opposite the first direction.20. The spinal stabilization system of claim 18, wherein the firstinsert is rotatable in the first through hole through an angle of lessthan 360° and the second insert is rotatable in the second through holethrough an angle of less than 360°.